This invention relates to a system for monitoring and collecting data on the viewing habits of television viewers. More specifically this invention relates to an apparatus and method for monitoring and collecting data on the viewing habits of television viewers employing local time coincidence coding.
Previous attempts to measure viewership patterns have been employed using intrusive measurement techniques (i.e. physical modification of the television receiver) relying on inferential measurement (i.e. measuring radio frequency of the local oscillator), and priori encoding tags inserted at the program origination point. It is desirable to make unilateral measurement of the natural program content using direct observation to determine viewership preferences. It is also desirable to make measurement of the natural program content without introducing changes into the television signal at the program origination point.
The present invention addresses the foregoing needs by providing an electronic television viewership monitoring system composed of a master unit which mixes an audio priori tag and a video priori tag on each channel of a television source signal within a dwelling, and a least one remote module which monitors the output of a respective television receiver via magnetic sensors and transmits a channel window interval signal having the priori tag encoded therein and a television status signal to the master unit. The master unit correspondingly identifies the channel being viewed by each respective television. The audience measurement system stores the viewership information and periodically reports the viewership information via a communications link to a central computer.